The population crisis, energy crises, regional droughts, prospective extra-terrestrial and oceanic development, as well as general environmental conditions, have spurred experimentation, commercial exploitation, and dedication of energy and resources to wholly artificial plant husbandry mechanisms, particularly directed to growth of nutritional plant life and human food stuffs. The technology relating to the foregoing is generally referred to as hydroponics. Due to the growing sophistication of hydroponic technology and the stringent environmental requirements, efficiency considerations are paramount in order to render the technology commercially viable. Strict environmental control required for this discipline includes nutrient quality monitoring, temperature and humidity regulation and carbon dioxide concentration flow control, light impingement control, and lastly, geometry and spacing control between individual growing plants.
Much effort has been dedicated to resolution of the general problems in hydroponics and perfecting those controls described above. As a result of these efforts, many examples of apparatus and methods directed to one or more of the foregoing problems are readily available in the marketplace and literature. Indeed, publications describe many hydroponic growth systems which incorporate features directed specifically to the foregoing concepts.
For example, U.S. Pat. No. 4,216,618 discloses a hydroponic assembly featuring a drive system incorporating variable pitch drive screws for accomplishing automatic separation of plants. The plants are contained in holders which engage the screws to move the plant along a trough at increasing intervals. To underscore the importance of plant spacing and the geometry of separation, the systems disclosed in U.S. Pat. No. 4,028,847, diverging angular dual troughs, and U.S. Pat. No. 4,035,949, a systematic and continuous separation accomplished by a greenhouse conveyor system are illustrated.
One of the more comprehensive disclosures relating to plant spacing is contained in U.S. Pat. No. 4,166,341, issued to Vestergaard. Vestergaard describes numerous systems and methods for achieving variable and increasing spacing in hydroponics. Among the featured automatic spacing apparatus are angularly diverging troughs, spring-loaded parallel separable troughs, and parallel channels merging into single channels, which in turn, eventually merge into one channel. Vestergaard also describes additional hydroponics concepts. First, a nutrient provision system wherein fresh nutrient is provided by squirting through outlets at the top of the main trough and into porous plant holder blocks containing the plant roots. These blocks are supported on an elongated trough-like member. The trough also serves as a liquid reservoir for the cultivation media, a root growth restraint mechanism, and a guide for movement of the blocks. Vestergaard also describes opposing, flexible opaque flaps which extend upwardly and outwardly above the trough thereby permitting translation of the plant through the trough but minimizing the quantity of light being able to enter the trough. This provision allows for carbon dioxide and hot and cold air to be delivered in a manner where the gas circulates slowly around the leaves, thereby reducing overall carbon dioxide requirements as well as minimizing the quantity of light entering the trough interior It is well known in the hydroponic art that light and nutrient lead to unwanted algae growth. Hence, the flaps are relied upon to deter algae growth.
A host of additional publications include descriptions which focus on many of the foregoing and other aspects of hydroponic farming structures and methods but none combine a total concept system which addresses spacing, energy, temperature, gas concentration, humidity, nutrient, and light control.